CPM - 2 | Pan Concrete Mixer

The CONSTMACH CPM-2 is a pan type concrete mixer that forms part of the company's CPM series of stationary mixing units. Within this series it is the largest model offered, positioned above the smaller CPM-0.5 and CPM-1 units. The numerical designation reflects the compacted concrete output per batch: the CPM-2 produces approximately 2,000 litres (2 m3) of compacted concrete in a single mixing cycle, compared with about 500 litres for the CPM-0.5 and 1,000 litres for the CPM-1. This places the CPM-2 in the segment intended for operations that require higher per-batch volumes while retaining the intensive, homogeneous mixing characteristics common to the pan mixer design.

The mixer operates on the pan principle, in which the mixing action is concentrated within a shallow circular pan rather than relying on the tumbling motion of a rotating drum. A central drive transmits rotation to mixing arms fitted with replaceable blades and scrapers. As the arms sweep through the material, they cut, fold and shear the mix, while scraper blades clear the pan floor and side walls to prevent material from accumulating against the surfaces. This forced mixing action distributes the cement paste evenly throughout the aggregate and is particularly effective with stiff, low-slump mixes that do not flow readily under their own weight.

The CPM-2 is rated with a charging (dry feed) volume of 3,000 litres, a fresh concrete volume of 2,500 litres and a compacted concrete volume of approximately 2,000 litres per batch. It is driven by a 55 kW motor, which is larger than the 22 kW of the CPM-0.5 and the 37 kW of the CPM-1, reflecting the greater pan diameter and batch mass. The difference between the charging, fresh and compacted volumes accounts for the reduction in bulk as loose dry materials are combined, wetted and consolidated into finished concrete.

Typical applications for the CPM-2 include precast concrete factories, concrete block and paving manufacturing lines, and stationary concrete batching plants where it serves as the central mixing unit. The intensive pan action suits the production of stiff and zero-slump concrete used in dry-cast and vibro-pressed products, as well as coloured concrete and fibre-reinforced mixes, where uniform distribution of pigments, fibres and cement is important to the consistency of the finished product.

The build of the CPM-2 is oriented towards resisting the abrasion that arises from continuous contact with aggregate. The side body is lined with 12 mm Hardox 450 wearing plates, the pan bottom with 12 mm St 52 plates, and the mixing arms with 25 mm Ni-Hard plates. These wear surfaces are replaceable, allowing the abrasion-exposed areas to be renewed independently of the main structure. The unit is fitted with SKF/FAG heavy duty bearings, and provisions such as a hydraulic discharge door, an emergency stop button, an access hatch and a maintenance door safety switch are part of the design.

Within a production facility, the CPM-2 sits between the material weighing and feeding system and the discharge point that supplies moulds, conveyors or transport equipment. Dry materials and cement are charged into the pan, water and admixtures are added, and after the mixing cycle the homogeneous concrete is released through the discharge door. As the highest-capacity model in the CPM pan mixer series, it is selected where a larger batch volume is required than the CPM-0.5 or CPM-1 can provide, while the working principle and component arrangement remain consistent across the range.